Structural responses of needles of conifer seedlings to acid rain treatment

摘要: summary The mesophyll ultrastructure of needles Norway spruce [Picea abies (L.) Karst.] and Scots pine (Pinus sylvestris L.) seedlings was examined in the course experimental acid rain treatment lasting three years. The pH 3-treated needle cells exhibited thicker granal packing their chloroplasts than dry control after one season's irrigation. Starch occurrence had decreased due to when whole hardening rest period considered. Chloroplast shapes were seen vary from ellipsoid irregular, especially 4 needles, divisions during hardening. mean area hardened state seasons, irrigation largest (10.3 μm2) which also contained smallest number dark-stained plastoglobuli. October reflected disturbances processes needles.